Advanced Configuration and Power Interface (ACPI) is a specification that makes hardware status information available to an operating system in computers including laptops, desktop, servers, etc. The ACPI also allows hardware resources to be manipulated. For example, ACPI assists in power management by allowing a computer system's peripherals to be powered on and off for improved power management. ACPI also allows the computer system to be turned on and off by external devices. For example, the touch of a mouse or the press of a key may wake up the computer system using ACPI.
Traditionally ACPI has been difficult to work with for a variety of reasons. First, ACPI is not written in the native assembly language of the computer system platform. Instead, ACPI has its own source and machine languages, ACPI Source Language (ASL) and ACPI Machine Language (AML), respectively. Because of its highly specialized use, there are relatively few ASL programmers. Furthermore, ASL has relatively few constructs because of its limited use. Furthermore, ACPI code is conventionally monolithic in its design. Consequently, this makes it difficult to port the ACPI code to other platforms or even to different configurations of the same platform. Thus, new ASL code needs to be written to work with different platforms. The limited number of ASL programmers makes writing new code all the more problematic and costly.
ACPI is composed of both static and interpretable tables. At bootup time, the system firmware constructs the static tables, which are consumed by the operating system. The interpretable tables are composed of AML. The AML is compiled and then merged into the system firmware. The operating system reads the AML from the interpretable tables and executes the architected interfaces, using an ACPI interpreter. In this fashion, the operating system manipulates hardware resources. Because the interpretable tables are merged into the system firmware, this conventional method lacks flexibility, scalability, and requires considerable time to re-program to accommodate various system configurations.
For example, conventionally developers write ACPI code to specify a particular configuration of a platform or its variance. Unfortunately, if even a minor hardware change is performed the design has to be modified. This requires that new AML code to be written and new tables to be merged into the system firmware. Thus, the conventional design is not portable or re-usable.
Furthermore, conventionally ACPI has required that a different system firmware ROM (Read Only Memory) or BIOS (Basic Input Output System) be used if there is a variance of the platform or if it supports more than one ACPI aware OS systems that have mutually exclusive ACPI requirements. A different system firmware ROM also had to be used if the same system is to support multiple operating systems.
Thus, one problem with conventional methods and systems for providing component information at run time is the difficulty in porting code to a different platform. Another problem with such methods and systems is the difficulty in porting code to a different configuration in the same platform. Another problem with such conventional methods and systems is that they are not very scalable. A still further problem is the additional development cost spent writing and testing new ASL code.